The friendly bacteria<span> living in the intestines provide protection from invading </span>bacteria<span>. ... The </span>digestive tract<span> also functions as a sensory organ to protect </span>us<span> from </span>harm<span>. ... Persistent vomiting </span>can<span> tear the esophagus and diarrhea may need the </span>help<span> of antibiotics to clear the offending </span>bacteria<span>.</span>
